在一个立体图形中 ,平面往往起着奠基的作用 ,借助平面的衬托 ,立体图形中点、线、面的位置关系才能显露地“立”起来 .因此 ,对于立体几何问题的探求 ,证明和运算往往依附某个特殊的平面 ,此平面的获取正是解题的关键所在 .如何迅速地、准确地捕捉这个关键平面呢 ?1　特写运算 In a three-dimensional figure, the plane often plays the role of laying the foundation. With the aid of the plane, the positional relationship of points, lines, and faces in a three-dimensional figure can be “stand up”. Therefore, for the exploration of three-dimensional geometric problems, proofs and calculations Often relying on a particular plane, the acquisition of this plane is the key to solving the problem. How to quickly and accurately capture this key plane?